Apparatus for deciphering cipher messages



1,643,546 A. G. DAMM APPARATUS FOR DECIPHERING- CIPHER MESSAGES sept. 27, 1927.

Filed Aug. 29. 1924 s Sheets-Sheet Sept. 27, 1927. 6

A. G. DAMM APPARATUS FOR DECIPHERING CIPHER MESSAGES Filed Aug. 29. 1924 s Sheets-Sheet 2 Sept. 27, 1927.

A. e. DAMM APPARATUS FOR DECIPHERING CIPHER MESSAGES s SheetS -Sheet 3 Filed Aug. 29. 1924 Patented Sept. 27, 1927.

NITED. STATES ARVID GERHARD DAMN,

OF RUNNING-E, SWEDEN.

APPARATUS FOR DECIPHERING CIPHEB MESSAGES.

Application filed August 29, 1924, Serial No.

This invention relates to an improved apparatus for deciphering cipher messages and more particularly to a combination of the apparatus described in the Creed British Patent Nr. 164,370 and known as the Creed printer and the apparatus'described in my U. S. Patent Nr. 1,540,107, dated June 2, 1925.

The object of my invention is to render it possible to decipher automatically telegrams which have been enciphered by means of my said apparatus, herebelow called the electrocryptographer.

The essential feature of my invention resides in this that the selector arms of the Greed printer, which according to the patent efi'ectthe stopping of the writing or type. wheel in the desired positions, are arranged to actuate electric contacts in circuits which according as the reversing switch of the electrocryptographer is in the one position or the other will pass through or past the commutator members or ciphering cylinders of the electrocryptographer and in which are inserted electromagnets adapted to actuate moveable members so as to bring thefsame' into the path of the stop arm'of the type wheel of the Creed printer for stopping said a wheel in the desired positions.

In the accompanying drawing a I "have shown one embodiment of my invention. Fig. 1 is a diagram showing the electric con nections of" the apparatus and Fig. 2 is a vertical longitudinal section of the Creed printer, illustratingthe alterations and additions embodying the present invention. Fig. 3 is. a perspective view of. a Creed printer many of the details being omitted as they are not necessary to a' complete understanding of the resent invention.

As is shown in Fig. 2 the writing or type wheel a of theCreed' printer is disposed in such-manner,"that thestop arm b thereof cannot be reached by the selector arms V ."The latter have each a'radially directed porl1 lOIl 100 adapted to actuate the moveable member of a contact .k t which will be closed when the corresponding selector arm V is turned by its spring 10d. The con-, tacts k t are, asswill: be more particularly described lierebelow, arranged to close the circuits of electromagnets Mt, mounted on the inner side of a stationaryring 43. The

734,904, and in Sweden September 10, 1828.

number of contacts 'k t and electromagnets Mt corresponds to the number of selector arms. The ring. 43 is formed-with an inwardly extending flange 43a having radial grooves 43?), in which angle levers 4! are swingably journalled, said levers being bx means of springs {l6 kept in sucha position, that they are not in the path of the stop arm I) of type wheel a. The outwardly swinging movement of the angle levers is limited by pins 47 inserted in said levers and striking the sides of the flange 43a. The number of angle levers 44 corresponds to the number of electromagnets Mt, and each angle lever is' provided with an armature 44a by means of which it can be actuated by the respective electromagnet Mt. When an angle lever is turned by an electromagh'et it will place itself in the path of the stop arm b of the type wheel a and stop said type.

wheel, whereupon the hammer 2'1 actuates the corresponding type arm in and a print is obtainedon the paper band fed between the type wheel and the platen n. The turning of the selector arm V is, as well known,

effected by a band which is 'fed into the" Creed printer and is perforated in accordance with the signs in the arriving telegrams. A telegram written by the electrocryptographer consists of the following parts:

a. An unciphered group of signs, indicating the position of the ke mechanisms at theend of the preceding te egram;

6. Address and ordinary service'remarks.

in clear text with the usual division in words or "corresponding groups of signs;

a. The telegram proper in cipher, divided into groups of an equal number of signs, for

instance five, and comprising complete groups only; and

d. An info ation in clear text of the number of cipher groups contained in the telegram. In order to make an automatic decipheringot such a telegram practicable, the.telegram must contain special signs, .herebelow called shift signs, which 'are not enciphered' and eflect an automatic reversion of the switch of the electrocryptographer, which.

'ciphered, after the adjustment of the ciphermg cylinders and the key disks into the initial positions stated in the telegram, said positions corresponding to the initial positions of the corresponding members of the electrocryptographer, by which the telegram has been enciphered, and after the adjust- -gram, is actuated by t ment of the aforesaid switch W, (Fig. 1)

v of current S.

for the rendering of clear text in the telegram (the position shown by dash lines in ig. 1) and also after the adjustmentof a switch Q (Fig. 1), described herebelow, for

automatic dec phering, the operations. of deciphering the telegram will be as follows.

y-the adjustment of the switch Q' for automatic deciphering the circuit of the mo- This circuit is as follows: from Q of the switch-Q, conductor 50, motor E,

conductor 51, contact 70,, the function of n which will be described-herebelow, and conductor 52 to the negative pole of the source The first 'sign on the perforated band fed into the Creed printer,- which sign is part of a clear text, causes the selector arm V corresponding to, said sign to be turned and close its contact 10, 5, Hereby the following circuits (Fig; 1) are closed. I

' (a) From the p'ositive 1e of the source of'current S through 'con uctor 49,;contacts 'Q and- Q of the switch ,Q, conductor 50,

conductor 94, contacts -W- and Wfijof the switch W, conductor'JQG, a commutator (12' described herebelow, conductor 91', contact le t, conductor 92, conductor 78t, contacts W and W of'the switchW, conductor '83,

83a, conductor 9311, the electromagnet Mt 'rcorresponding 'to the actuated selector arm V of the Creed printer, a-nd conductor 52 rent S.

contacts Q Q ofthe switch Q, conductor to the .negatiye. pole of the source. of .cur-

.-(-b From the positive pole of the source I "of current'to' the contact k t. the same way as under (a) and thereafter through conductor 92, conductor 98, conductor 66, conductor 65, solenoids S S and, according as one or moreof the contacts k k k is, actuated by the key disks N N -N N are closed through one or more of the con- ,ducmrs 55, 54, 56, 57, 5s and 62, '61, 59, 6O respectively, through one or more-.of-thev contacts f f f of the secondary key V conductor 53', conductor 68, contacts Q of the switch Q and conductor back rent S. v Sc) The same way as under (b) vup to and inc udilig conductor 66, and therefrom to the negative pole of the' source, of ourthroutgh conductors 67, the parallelly connecte solenoids S 1,,S 2,,S,3 and S 4,.conductors 68 and'conductor 68, switch contacts Q Q and conductor 70 back to the negative pole of the source of current S.

The circuit described under (a) elfects the stopping of the type wheel a of the Creed printer in such a position that the type arm 7 k, corresponding to the selector arm actu- Med and thus to thehgst sign of the telee hammer 21 (Fig. 2) and prints said si 11 on the paper band fed between the type .w eel a and the platen n. ,The circuit described under (6) elfects a turning of one or both of the ciphering cylinders C C The circuit described under (0') eifectsa turning ofthe key disks N N N N;.

The same operations will be repeated for each sign of the clear text of the telegram. The empty spaces on the perforated band I feed into the Creed printer, which spaces correspond to the spaces between the words of the. clear text of the telegram, effect the actuating of a selector arm marked V m in Fig. '1. When this selector arm is turned, it breaks a contact la e and closes a contact k m and thereby completes the following circuit: from the positive pole of ,the source of current S through conductor 49, switch contacts Q Q conductor 50, conductor 94, switch contacts W W conductor 96, commutator ap, conductor 916,

'switch contacts W W conductor 77, con

tact la m, conductor 95, switch contacts W W conductor 93m, Ielectroma-gnet Mm and conductor 52 back to the negative pole of the source of current SQ, Hereb the electromagnet Mm actuates an angle ever 44m, which arrests the-type wheel of the Creed printer in such a position that a space between the two words is obtained in the telegram typed by the Creed printer. I

Upon the clear text of the telegram. follows "ashift sign, the purpose of which is to effect a re-adjustm'ent ofthe electro- -cryptographer from clear text'to deciphering, This shift sign effects the turning ofa no v selector arm V w of the Creed printer,

whereupon the corresponding contact 72, 1;

" closes the following circuit: from thepositive pole of the source of current S through conductor 49, switch contacts "Q Q con-- ductor 50, conductor 94, switch contacts W W conductor 96, commutator ap, conductor 91a, contacts k t, conductor99, electromagnet S conductor 100 and conductor 52 back 'tothe negative pole of the source of current.

The electromagnet S now actuates a reversing device ,L (diagrammatically indicated in'Fig. 1) operating the switch W, s'o that the latter is re-ad justed to the position shown 3 in full lines in Fig.1.

-Now',- .when the firstcipher sign ofthe telegram causes a turning of the corresponding select-o1" arm of the Creed printer, the

contact 'k t actuated by said selector arm closes the following circuits:

(d) From the positivepole of the soure.

Q of current S through conductor 49, switch through conductor 92,0onductor 98, conductor arm actuated, conductor 92, conductor 78t,'

switch contactsW W conductor 76, contact 7e 2,, ciphering cylinders 0,, contact kj, conductor 75, switch contacts Q Q conductor 9315, an electromagnet Mt and conductor 52 back .to the negative pole of the source of current S.

(re) From the positive pole of the source ofcurrent S the same we as under (d) up to and including contact t and therefrom 66, conductor 65, solenoids S S and according as one or more of the contacts 1a,, 10,, k is, actuated by the key disks N N,, N,,, N 4 are closed, through one or more of the conductors 55, 54, 5e, 57, 5s and c2, 61, 59, 60 respectively, one or more of the contacts f,, f2 f3, I", of the secondary key V conductor 53, conductor 68, contacts Q, Q, and condoctor 70 back to the negative pole of the source of current S.

' (f) From the positive pole of the source of current S the same way asunder (e) up to and including conductor 66, therefrom through conductors 67, the parallelly connected solenoids S 1, S 2, S 3 and S 4, condoctors 68 and conductor 68, switch contacts-Q,,Q and conductor 70 back to the negative pole of the source of current S.

V 'The circuit described under (d) passes through the electromagnet Mt, corresponding to that sign of the original telegram text,

printer, is evident from the fact that the,

which is rendered by the first cipher sign of the telegram received. The circuit described under (icauses oneor both of the ciphering.

cylinders C C to be turned. 5 The circuit described under (f) causes the key disks N N N N to be turned.

The circuit described under (d) conscqucntly causes'a deciphering. of the firstcipherusign of the telegram. "Thata correct deciphering is obtained, provided the telegram text received be correctly rendered on the perforated band fed into the Creed ciphering cylinders C C5 and the key disks N,, N,, N N have been turned in exactly the same manner as the corres 'onding mem bers of the electrocryptograp er by wh1ch the telegram has originallybeen written while the Creed rinter is rendering the clear text of the te egram.

- Forevery followin Blgll on the perforated band fed into the reed printer, and corresponding to a cipher'sign, the operations just described will" be repeated When five subsequent signs have been deciphe'red, there follows on the space correspon ing the space between known way by perforations.

erforated bandan empty t be turi ed and close the contact k m. The function of these two'contacts will be described herebelow. 1

During the production of the cipher by the electrocryptographer said spaces between groups of signs were obtained automatically,

special adjustment of the ciwithout any mechanisms phering cylinders and the key Duringthe deciphering o is, consequently, necessary that, whi e, each space between groups of signs is passing through the Creed printer, the circuits above the tele am it mentioned under (e) and (f) are disconnect ed, which is performed by the above mentioned commutator a, described herebelow.

Upon the ciphered part of the telegram follows a shift sign causing selector arm V w to be turned, whereby the, following circuit is closed:

From the positivepole of thesource of current through conductor 49, contacts Q, and Q ,'conductor 50, conductor 50b, commutator a conductor 90,, commutator up, conductor 91a, contact k t, conductor'99, electromagnet S conductor 100, conductor 52 to the negative pole of the source of current. Hereby the electromagnet S is recxcited, whereby the reversing device L is actuated and re-adjusts the switch W for clear text. The last part of the'telegram, containing'iu clear text-an information of the number of groups of cipher signs, is

exactly as above described concerning the rendering of the first part of the telegram.

As above mentioned the telegram received appears in the shape of a pa 1' band with Morse-signs, rendered in t e commonly occasional B deficiency in the mechanical fhnctions of the apparatus, by which the erforated Ill) bands are produced, or, in wire ess teleg raphy, also on account of atmos heric disv turbances, whole signs or parts t ereof may disappear, and in such cases it ma also occur that a combined sign is divide into two or more shorter signs.

The ciphered part ofthe tele am, which 7 originally contained groups o five signs, may thus contain, groups of agreater or smaller number of sigiisthan five.

The electroc ptographer, however, effects .a turning of t e keys for every sign enciphered or deciphere and a necessary condition for obtaining a, correct -deciphering is that the electrocryptographer prior to the l encipherin or deciphering of thesame sign,

has eifecte an equah-i'iumber of such turnings. Therefore, if any sign-is lost or. added, that synchronism is'broken and must be restored, if the sequence shallfbecorrect.

conducting and non-conductin This purpose is servedby the arresting device 'which is built upon co-operation between the commutators a, and a diagrammatically shown in Fig. 1, the selector arm for empty spaces V m, the cont-acts 70 0 and Is m, the electromagnet 7m, and the contact kp actuated thereby.

This arresting device willbe in function as long as the switch W is adjusted for deciphering and arrest the Creedprinter and thereby also the electrocryptographer as soon as any fault in the successive division into five-sign-groups influences the selector-device of the Creed printer. The circumferences of the commutators a and (1,, which are both driven from the driving axle 2 of the Creedprinter with such a ratio of gear, that'they rotate-one revolution while said axle rotates six revolutions, are divided into electrically portions in such manner that one sixth o the circumference of a and five sixths of the circumference of a are electrically conducting, while the .other portions are non-conducting a and a. are so adjusted in relation to each other e that the circuit through (1 is closed while the circuit through a is broken and so'that this occurs exactly at the moments when emptyv spaces between groups on the perforated band are passing.

If forreasons above-mentioned a space has occurred so that a group of too small a number of signs has been formed, the consequence will be that, when said space actuates the selector device of the Creed printer, the selector arm 'v m forthe empty space is turned, whereby the following circuit is closed. From the positive pole of the source of current through conductor 49, contacts Q and Q2, conductor 50, conductor 50", com- I mutator a conductor 90, conductor 96, contacts W and conductor 97, contact current.

70 m, conductor 88, contacts W' and W conductor 89, electromagnet M and conductor 52 to the negative pole of the source of -Hereby the electromagnet M is excited and act-uates'contactkp so that the same is broken, whereby the circuit for the motor of the'Creed printer is broken and the letter and consequently the Creed printer are stopped. The switch 'Q, must then be readjusted for manual deciphering (the position shown by dash lines) and thereafter the number of signs missing in the complete group are pressed down by hand on the key-. board of the- 'electrocryptographer.

Then

' the perforated band is moved by hand to next empty space, whereupon-the apparatusis ready to continue its work.

. contain too many signs, the. circuit is closed 'throu h the comrriuator a when the sixth sign 0 'the group actuates the selector device of the Creed printer. This circuit is the following one: from the positive pole of the source of current through conductor 49, conductor 50, conductor 50a, commutator a conductor 87, contact k c, conductor 8 8,contacts W and W conductor 89, electromagnet Mic and conductor 52 .to the negative pole of the source of current. Hereby the electromagnet Mk is excited and actuates the contact lap, so that the circuit of the motor of the Creed printer is broken, whereupon. the motor and, consequently, also the Creed printer are stopped. The perforated band in this case must be moved by hand'to the next empty space, whereupon the apparatus is ready to continue its work.

. In order to indicate after the Greed. printer has stopped wherein the fault consists and how many signs of a group have passed the commutator a is furnished with an index and a dial graduated 0-5. If the index steps on 0, this indicates that the group has contained too many signs, but if the .dial sto s on any of the other fi ures, said figure in icates the number of adjustments the electrocryptographer has already effected in respect of the group in question. From the above mentioned it appears that the commutator a when spaces between groups are passing the Creed printer breaks also the circuits described above under (6) and ),-whereby turnings of the ciphermg cylin ers and key mechanisms are avoided.

In the Creed printer the paper band on which the telegram is produced is 'iven' one feeding step for every revolution of the driving axle. In the present case the feeding movement of this band therefore must be arrested every time a space between two groups passes in deciphering, in order that the electromagnet Mh is excited, the pawl is kept in engagement with the ratchet wheel and will thus in each rocking movement of the angle arm 3 turn the ratchet wheel one step,- but as soon as the excitation ceases, the pawl is disengaged by the influence of a spiral spring z on account whereof the rockmg movement of the angle lever will not cause the ratchet wheel to be turned.

The circuit in which the electromagnet is included is the following one: from the posivtive pole of the source of current through conductor 49, contacts Q Q conductor 50, .conductor 50b, commutator a conductor 101, electromagnet Mh, conductor 102 and conductor 52 to the negative pole of the source of current. This circuit according to the mensioned and adjusted that it closes the circuit only the moment after the respective contact k t has been closed and breaks the circuit somewhat before the respective contact k t is broken. Consequently, the contacts k t are current-less during the moments of time when they are closed or broken wherefore no formation of sparks can be caused in the same.

i The commutator up is placed on the driving axle of the Creed printer said axle determining the sequence of time of the different functions of the apparatus.

If for any reason the Greed. printer be out of gear so that an automatic deciphering would be made impossible for the time being, the deciphering can be continued manually. The switch Q, in such case is reversed to its position for manual deciphering which is shown by dash lines in Fig. 1, and

when the ciphering cylinders and the key disks have been adjusted into'the initial positions indicated in the telegram and the switch W has been adjusted for the rendering of clear text, viz, to the position shown by dash lines in Fig. 1, that key of keyboard of electrocryptographer is pressed down which carries thefirst sign of the telegram, said sign being a part of clear text. Hereby the following circuits are closed: (g) From the. positive pole of the source of current through conductor 49, contacts Q Q conductors 66,72, solenoid S 111, conductors 84, 836, contacts Q Q conductor 83, contacts W W conductor 7 8t, contact spring k t, member St and conductors 802, to the negative pole of the source of current.

(h) From the positive pole of the sourceof current through conductor 49, contacts' Q Q conductors 66, 81', solenoid SJ, conductors 82$, 7 8t, contact spring k t, member St and conductors t, 70 to the negative pole ofthe source of current. i

('2) From the positive pole of the source of current through conductor 49, contacts Q Q conductors 66, 65, solenoids S S and according as one or more of' the con tacts 75,, I0 10,, lo, actuated by the key disks N N N N are closed throughv one or more of conductors 55, 54, 56, 5.7, 58 and '59, 60 respectively, through one or more of the contactsj f f f, of the secondary key o conductors 53, 68 contacts conductor 7915, contact spring k t,

f member St" and conductors 80t, 70 to thenegative-pole of the source of current.

( From the positive pole of the source 1 i of current through conductor 49, contacts source of current.

When the circuit-described under (g) is closed, the solenoid 8 a: of that key of the cipher-typewriter is excited, which carries thesame sign as the key depressed in the key-board of the electrocryptog'rapher.

S 3, S 4, con-- When circuit described under (72.) is

closed, the solenoid S t is excited and actuates that key of the copy-typewriter, which carries the same sign as the key depressed in the key-board of. the electrocry'tographer.

The circuit described-under cylinders C C The circuit described under (j) effects a' At the spaces between words of the clear text the key Tm of the key-board of the electrocryptographer is depressed, whereby the following circuits are closed:

effects a turn ng of one or both of the ciphering (is) From the positive pole of the source of current through conductor 49, contacts Q Q conductors 66, 72, conductor 73m, solenoid S m, conductor 86, contacts W W conductor 78m, contact spring 70 m,

' member Sm andconductors 80m, 70 to the negative pole of the source of current. By the excitation of the solenoid S m the spacmgd key of the cipher-typewriter'is actuate (Z) From the positive pole of the source of current through conductor 49, contacts.

Q Q conductors 66, 81, solenoid 8 m, conductors 82a, 7 8m, contact spring 10 m,

member Sm and conductors 80m, 70 to the negative pole of the source of current. B the excitation of the solenoid Sgm, whic actuates the spacing key of the copy-typewriter, the spaces between words are obtained in the copy.

(m) From the positive pole of the source of current through conductor 49, contacts Q, Q conductors 66, 65, solenoids S S and according as one or more of the contacts 70 70,, k is, actuated by the key disks 1, 2,

61, 59, 60 respectively through one or more of the contacts f, i f, of the secondary key '0 con uctors 53, 68, 79m, contact, sprin 10 m, member Sm and conductors 80m, 70 130 the negative pole of the source of current. This circuit effects a turning '0 N N, are closed, through one or; more of conductors 55, 54, 56, 57, 58 and 62,

one or both of the ciphering cylinders C 0,. (n) From the positive pole of the source of current through conductor 49, contacts Q Q conductors 66 and 67, the parallelly connected solenoids S 1, S 2, S 3, S 4, cohductors 68 68, 79m, contact spring 70 m, member Sm and conductors 80m, 70 to the negative pole of the source of current. This circuit causes the key disks N N N N, to be turned.

When the first, unciphered part of the telegram has been dealt with as described above, the switch W is reversed to' deciphering position as indicated in full lines in Fig. 1. That key of the keyboard of the electrocryptographer which carries the same sign as the first cipher signof the telegram isdepressed, whereby the following circuits are c osed:

From the positive pole of the source of current through conductor 49, contacts Q Q conductors 66, ,72, 732;, solenoid S 27,

conductor 74, contacts Q Q conductor 75,,

contact 72,,t, ciphering cylinders C C contact lo t, conductor 76, contacts W ,'W conductor 78!, contact sprlng 70 1!, member St and conductors 806, 70 to the negative pole 'der h), (i) and (j) are closed, whereby theof the source of current;- 'When this circuit is closed, the solenoid S t is excited and actuates the key of the cipher-typewriter corresponding. to that sign of the original telegram, which has been rendered by the first" cipher sign of the telegram received. This circuit consequently effects a deciphering of the first cipher sign of the telegram. Beside this circuit the circuits described unsign 1s obtained on the co y-typewriter and 1 Q conductors-66 "and 65, solenoids S4, S

the cipherihg cylinders C and the key disks N IN N5, N are turned. For

every followlng sign of the telegram corresponding to a cipher sign the described operation is repeated.

The device for the adjustment of cylin .de'rs C ,.C into their initial position is the" same as described in my co ending application Serial --Nr. 540,234 an the clrcult for same is in this case the following one:

From the positive pole of the source of current through conductor e9, contacts Q conductors 61, 62, 63 andconductor '55, 001i 'tacts'lc and 70 conductors 64, contacts'f and f disks 0,, and 0 respectively, contacts f andjf conductor 71, contacts W ,{conductors 69 and 70 to the negative pole of the source of current.

Having now described my invention, what lclaimisz. 4

1. The combination with a rintin'g mechanism of the character speci ed havine' lector arms, a printing wheel and a stop arm for said wheel, and an electro-cryptographic mechanism comprising a reversing switch and ciphering cylinders; of an electric contact pertaining to each selector arm, said contacts closing circuits through or past said cylinders, an electro-ma net in each circuit and a movable member ior each mag-- net, which member when actuated is placed in the path of'said stop-arm to selectively stop said wheel.

Y 2. A combination as set forth in claim 1,

in which one of the selector arms of the printing mechanism, which is adapted to be influencedby a so called shift sign of the telegram to be deciphered, is arranged to close the circuit of an electromagnet ar-" the other commutator are electrically conducting and the remaining sixth is non-con ducting, the said commutators being so adjusted in relation to each other and to the printing mechanism that the circuit through the first mentioned commutator is closed each time a space on the perforated band fed into said mechanism passes the selector deviceof the latter at the same time as the circuit throu h the other commutator is broken, the circuits of the-commutators including an electromagnet which when ex:

' cited breaks'a contact in the circuit of the motor drivingsaid mechanism each of said circuits mclu i selector arm of the printing mechanism ng also one contact, said contactsbemg arranged to be actuated by thewhich is adapted to effect spaces in the telegram being written in such a manner that said selector arm when in idle position keeps the contactin the circuit. of the first mentioned commutator closed and the contactin the circuit of the other commutator broken but when it is .actuat'ed fby the elec-- tor device of the printing mechanism breaks the first mentioned contact d closes the other, substantially as and rom the purpose set forth.

I In testimony whereof scribed my name. A

' -"ARVID GERHARD DAMM.

Ihave hereunto sub-- 

